Uniaxial experimental study of the acoustic emission and deformation behavior of composite rock based on 3D digital image correlation(DIC)

作     者：Jian-Long Cheng Sheng-Qi Yang Kui Chen Dan Ma Feng-Yuan Li Li-Ming Wang 

作者机构：State Key Laboratory for Geomechanics and Deep Underground EngineeringSchool of Mechanics and Civil Engineering China University of Mining and Technology State Key Laboratory of Shield Machine and Boring TechnologyChina Railway Tunnel Group Co. Ltd. 

出 版 物：《Acta Mechanica Sinica》 (力学学报（英文版）)

年 卷 期：2017年第33卷第6期

页      面：999-1021页

核心收录：

学科分类：08[工学] 080104[工学-工程力学] 0815[工学-水利工程] 0802[工学-机械工程] 0701[理学-数学] 0801[工学-力学（可授工学、理学学位）] 0702[理学-物理学] 

基　　金：supported by the National Basic Research 973 Program of China (Grant 2014CB046905) the Natural Science Foundation of Jiangsu Province for Distinguished Young Scholars (Grant BK20150005) the Fundamental Research Funds for the Central Universities (China University of Mining and Technology) (Grant 2014XT03) the innovation research project for academic graduate of Jiangsu Province (Grant KYLX16_0536) 

主　　题：Uniaxial compression tests on composite rock Anisotropy Elastic constant Failure mode 3D digital image correlation Acoustic emission Strain field 

摘      要：In this paper, uniaxial compression tests were carried out on a series of composite rock specimens with different dip angles, which were made from two types of rock-like material with different strength. The acoustic emission technique was used to monitor the acoustic signal characteristics of composite rock specimens during the entire loading process. At the same time, an optical non-contact 3 D digital image correlation technique was used to study the evolution of axial strain field and the maximal strain field before and after the peak strength at different stress levels during the loading process. The effect of bedding plane inclination on the deformation and strength during uniaxial loading was analyzed. The methods of solving the elastic constants of hard and weak rock were described. The damage evolution process, deformation and failure mechanism, and failure mode during uniaxial loading were fully determined. The experimental results show that the θ = 0?–45?specimens had obvious plastic deformation during loading, and the brittleness of the θ = 60?–90?specimens gradually increased during the loading process. When the anisotropic angle θincreased from 0?to 90?, the peak strength, peak strain,and apparent elastic modulus all decreased initially and then increased. The failure mode of the composite rock specimen during uniaxial loading can be divided into three categories:tensile fracture across the discontinuities(θ = 0?–30?), slid-ing failure along the discontinuities(θ = 45?–75?), and tensile-split along the discontinuities(θ = 90?). The axial strain of the weak and hard rock layers in the composite rock specimen during the loading process was significantly different from that of the θ = 0?–45?specimens and was almost the same as that of the θ = 60?–90?specimens. As for the strain localization highlighted in the maximum principal strain field, the θ = 0?–30?specimens appeared in the rock matrix approximately parallel to the loading direction,while in the θ =